Things came to a conflict under Trajan. In the earlier years of his government he had made no essential change in eastern affairs, apart from the conversion of the two client-states hitherto subsisting on the border of the Syrian desert--the Nabataean of Petra and the Jewish of Caesarea Paneas--into administrative districts directly Roman (A.D. 106). The relations with the ruler of the Parthian kingdom at that time, king Pacorus, were not the most friendly,[46] but it was only under his brother and successor Chosroes that a rupture took place, and that again concerning Armenia. The Parthians were to blame for it. When Trajan bestowed the vacated throne of the Armenian king on Axidares the son of Pacorus, he kept within the limits of his right; but king Chosroes described this personage as incapable of governing, and arbitrarily installed in his stead another son of Pacorus, Parthomasiris, as king.[47] The answer to this was the Roman declaration of war. Trajan left the capital towards the end of the year 114,[48] to put himself at the head of the Roman troops of the East, which were certainly once more found in the deepest degeneracy, but were reorganised in all haste by the emperor, and reinforced besides by better legions brought up from Pannonia.[49] Envoys of the Parthian king met him at Athens; but they had nothing to offer except the information that Parthomasiris was ready to accept Armenia as a Roman fief, and were dismissed. The war began. In the first conflicts on the Euphrates the Romans fared worst;[50] but when the old emperor, ready to fight and accustomed to victory, placed himself at the head of the troops in the spring of 115, the Orientals submitted to him almost without resistance. Moreover, among the Parthians civil war once more prevailed, and a pretender, Manisarus, had appeared against Chosroes. From Antioch the emperor marched to the Euphrates and farther northward as far as the most northerly legion-camp Satala in Lesser Armenia, whence he advanced into Armenia and took the direction of Artaxata. On the way Parthomasiris appeared in Elegeia and took the diadem from his head, in the hope of procuring investiture through this humiliation, as Tiridates had once done. But Trajan was resolved to make this vassal-state a province, and to shift the eastern frontier of the empire generally. This he declared to the Parthian prince before the assembled army, and directed him with his suite to quit at once the camp and the kingdom; thereupon a tumult took place, in which the pretender lost his life. Armenia yielded to its fate, and became a Roman governorship. The princes also of the Caucasian tribes, the Albani, the Iberi, farther on toward the Black Sea the Apsilae, the Colchi, the Heniochi, the Lazi, and various others, even those of the trans-Caucasian Sarmatae, were confirmed in the relation of vassalage, or now subjected to it. Trajan thereupon advanced into the territory of the Parthians and occupied Mesopotamia.